Gradient isotopique le long de l'arc des Nouvelles Hébrides (Vanuatu, Pacifique sud-ouest); collision de la zone d'Entrecasteaux et hétérogénéité des sources mantelliques [Isotopic gradient along the New Hebrides Arc (Vanuatu, Southwest Pacific); collision of the d'Entrecasteaux Zone and heterogeneity of mantle sources]
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doi: 10.1016/S1251-8050(97)87453-8 |
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| Alternate Title: | Isotopic gradient along the New Hebrides Arc (Vanuatu, Southwest Pacific); collision of the d'Entrecasteaux Zone and heterogeneity of mantle sources |
| Authors: | Laporte, C.; Briqueu, L.; Cluzel, D.; Eissen, J. P. |
| Author Affiliations: | Primary: Université Française du Pacifique, Noumea, New Caledonia Other: Université de Montpellier II, Montpellier, France ORSTOM, Plouzane, France |
| Volume Title: | Comptes Rendus de l'Académie des Sciences, Série II. Sciences de la Terre et des Planètes |
| Source: | Comptes Rendus de l'Académie des Sciences, Série II. Sciences de la Terre et des Planètes, 326(2), p.101-106. Publisher: Gauthier-Villars, Montrouge, France. ISSN: 1251-8050 |
| Publication Date: | 1998 |
| Note: | In French with English summary. 17 refs.; 1 table |
| Summary: | The recent volcanic activity of the New Hebrides arc (Vanuatu) has been influenced by the collision with the d'Entrecasteaux Zone, the composition of which remains uncertain. New trace elements and isotopic data from these lavas allow previous interpretations of compositional gradients along the arc to be qualified. The geochemical compositions of lavas display abrupt changes from calc-alkaline compositions straight in front of the collision zone, to arc-tholeiite on both sides. In contrast, isotopic compositions display a progressive variation related to less and less enriched sources away from the collision zone, evolving toward 'normal' MORB-type sources. Such a trend suggests that two types of contamination have occurred: in front of the collision zone, a magmatic contamination due to the subduction of an older lithosphere (206Pb/204Pb trend) and contamination by an "enriched-type" mantle component (Dupal feature). |
| Sections: | Geochemistry |
| Subsections: | Igneous rocks |
| Subjects: | Alkaline earth metals; Calc-alkalic composition; Chemical composition; Heterogeneity; Island arcs; Isotope ratios; Isotopes; Lava; Lead; Magma contamination; Mantle; Metals; Nd-144/Nd-143; Neodymium; Pb-206/Pb-204; Radioactive isotopes; Rare earths; Sr-87/Sr-86; Stable isotopes; Strontium; Trace elements; Melanesia; Oceania; Pacific Ocean; Vanuatu; Entrecasteaux Zone |
| Abstract Numbers: | 99M/556 |
| Record ID: | 1998040846 |
| Copyright Information: | GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique, Vandoeuvre-les-Nancy, France |
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